We have designed and assembled two generations of integrated micro-optical systems that deliver pump light and detect broadband laser-induced fluorescence in micro-fluidic separation systems employing electrochromatography. The goal is to maintain the sensitivity attainable with larger, tabletop machines while decreasing package size and increasing throughput. One type of micro-optical system uses vertical-cavity surface-emitting lasers (VCSELs) as the excitation source. Light from the VCSELs is relayed with four-level surface relief diffractive optical elements (DOEs) and delivered to the chemical volume through substrate-mode propagation. Indirect fluorescence from dye- quenched chemical species is collected and collimated with a high numerical aperture DOE. A filter blocks the excitation wavelength, and the resulting signal is detected as the chemical separation proceeds. Variations of this original design include changing the combination of reflective and transmissive DOEs and optimizing the high numerical aperture DOE with a rotationally symmetric iterative discrete on-axis algorithm. We will discuss the result of these implemented optimizations.

Date Published: 27 April 2000
PDF: 9 pages
Proc. SPIE 3952, Optoelectronic Interconnects VII; Photonics Packaging and Integration II, (27 April 2000); doi: 10.1117/12.384415

Published in SPIE Proceedings Vol. 3952:
Optoelectronic Interconnects VII; Photonics Packaging and Integration II
Michael R. Feldman; Richard Liqiang Li; Michael R. Feldman; Richard Liqiang Li; W. Brian Matkin; Suning Tang, Editor(s)